Fractional-distillation process and apparatus



APPLICATION 'FILED MAPS. 30,11916.

pagante@ Aug 2,1921

2 SHEETS-SHEET 1y' INVENTOR.

ATTORNEY v. iNmhNNwN @Sv v. T. GALC'HIST.; -ERACTIAONAL D ISTIL'LATION PROCESS AND APPARATUS.

'APPLICATION FILED-MAH. 30. 1916. A

2.SHEETS-SHEET 2 Z W/T/VESSES.'

the vcity and county of- San Francisco, tate iJNlTED STATES PATENTl oFF1cE.

VINCENT T. -GII-fCHRIST, OF SAN FRANCISCO,A CALIFORNIA, ASSIGNOR, BYMMESNE 'ASSIGNMENTS T0 SUPERIORREFINING PROCESS CO., OF SAN FOR/NIA, A CORPORATION OF CALIFORNIA.

FRANCISCO, CALI- y FRACTIONAL-DISTILLATION PROCESS AJSI'D APPARATUS Specification' of Letters Patent.

Patented Aug. 2, 1921.

Application filed March 30, 1916.' SerialNo. 87,860.

T all whom it' may concern.'

Be it known that I, VINCENT T. GILoHnIsT, a citizen of the United States, residm at of California, have invented a new and useful Improvement in -Fractional-Distillation I Processes and-Apparatus, of which the following is a specification.

This invention relates particularly to fractionating or separating from crude petroleum vapors the various'products of lighter specific gravities, such as gasolene, engine dis tillates, kerosene and the like, with the par-- ticular object of effecting such separation with a minimum expenditure of fuel.

In the specification and thel annexed drawings, I illustrate the invention in the formthat I consider the best, 'but it is to be understood that I do not limit myself to such form, becausel the Vsaid invention may be embodied in other forms; it is also to be understood that in and by the claims following the description I desire to cover the invention in whatever form it may be embodied.

,The products derived 'from crude petroleum are taken oft' at various temperatures, the lighter products of lower specific gravity are given ofl' at relatively low vaporizing temperatures and the products of greater specific gravity have correspondingly higher vaporization temperatures. Vapors derived from crude petroleum at any temperature contain a variable quantity of.

a series of hydrocarbons with different vaporizing temperatures, hence it is possible with these vapors to condense a portion, the residual vapo-r after such 'fractional condensation being of a lower temperature thanv that of the original vapor. If the fractional condensation occurs in a series of stages, the condensates will vary in specific gravity, the first condensate being the heavier and the final condensate the lighter. ,With each fractional condensation both latent and sensible heat is given out and it is one of the objects of this invention to utilize thisheat heretofore lost in the condensing` medium employed. usually water. The heat is utilized in '.'efractionating the partial condensates, *nis being the medium employed to .next still operating-at a higher temperature,

and so on through the various stages until the last cut is made.

In the accompanying two sheets of drawings,

Figure l is a diagrammatic fro-nt elevation of a distillation apparatus combined and arranged in accordance with this invention.

F ig. 2 is avertical cross section of a primary still with a superimposed dephlegmaftor column.

Fig. 3 is a. plan view of the same in perspective taken on the line III-III, Eig. 2.

The apparatus for carrying out this'lproc* ess consists of a series of prima-1 and a series of secondary condensing units, combined and interconnected in a novel manner that will be l more particularly described hereinafter.

In detail the primary unit illustrated in Fig. 2 consists of the dome l having the heating coil 2 arranged in the bottom thereof, the various return sections of the coil are separated by upstanding balileplates resting upon the bottom of the dome l and alternately connected t0 alternate sides of the dome, to cause the condensates contained within the dome to follow a tortuous path over rthe heating coil from the inlet to the outlet of-the dome. The vapors evolved within the dome pass therefrom to the outlet pipe 5 leading into the reflux evaporator 6 preferably located4 immediately abovejthe dome.l This reiux evaporator consists of a vertical, cylindrical chamber filled With some suitable condensing media, that preferred by me being a roll of what is knownV diameter of the chamber preventing the incoming vapors from short circuiting up the sides, compelling them to follow a tortuous path through the condensing media 7. The vapors escape through the outlet 'pipe 8 to the heating coil in the secondary still to which it is connected.

The secondary still F is similar to the primary still inevery respect, except that the capacity may be less, as it handles a reduced Yquantity of vapor. The arrangement of the heating coils and the inlet and outlets are alike, the description of the primary still serving for both.

The apparatus required to perform the required functions of partial condensation and refractionation of the condensate, consists of one of several sets or seiies of units; the number of units required depends upon the character of the petroleum being treated and the number of commodities desired removed. The crude oil still or retort Y .for producing the crude vapor and cgndensers for liquefying the' various commodities produced, may be of any of the well known types, all of which are available in the practice of this invention and not being gerniane thereto details thereof are omitted from the illustration and description. The crude oil vapors are given out from the ciude oil still Y heated 'by the burner Z at a temperature between 500O and 600o Fahrenheit, and pass through the pipe 10 into the heating coils in the first primary still A, 'The condensates condensed within the heating coil in the first primary still pass therefrom through the pipe 11, where they drop into the separator 12 from which they flow through the pipe 13 to the pump 14 that forces them under pressure through the pipe .15 against the check valve 16, causing the condensates to flow through the pipe 17 into the second primary still B. In the still B the condensate follows a toituous course from the inlet 17 between the baiiie plates over the heating coil in the bottom of the still, giving QH by evaporation its lighter vapors, the remaining condensates flowing out of the still B through the outlet 18 into the pump 19 which forces it under pressure through the pipe 20 into the secondary still F, wherein it flows its tortuous'course between the baffle plates over the heating coil .in the bottom of the secondary still F, the

remaining condensates escaping throughthe outlet 21 and flowing back through the inlet 22 to the primary still A wherein it travels A a tortuous course between the baflie plates over the heating coil therein, giving off' by evaporation its lighter vapors by absorbing the heat of the heating coil, until it passes out of the primary still A through the outlet 23, having given off all of its lighter constituent vapors. The vapors thus generated in the primary still A pass upward A clearly defined commercial cut.

F1, which may be water cooled or of any other type. The precipitation of condensate within the heating coil in the bottom of the secondary still F flows into the separator 26, and flows back through the pipe 27, through the vapor trap 28, and is distributed by the perforated pipe into the top ofthe dephlegmator A1 and over -the condensing surface therein .which it cools. promoting the condensing of the rising vapor from the still A, be'ing'itself evaporized by the heat of such rising vapors, draining back through the primary still A and escaping therefrom through the pipe 23, to be re-iun through the crude oil still or otherwise disposed of. The lighter vapors passing from the heating coil in the bottom of the secondary still F pass through the pipe 29 into the condenser F, the products of this condenser being a In this first step A and F all of the products having an evaporating point at or near the heat of the incoming crude oil vapors, for example, between 500 and 600 degrees` Fahrenheit are given off, such vapors passing from the dome of the secondary still F through the pipe 24 to the condenser F.

The vapors escaping from the heating coil in the first primary still A give off their condensates in the .separator 12 and pass through Athe check valve 30 into the pipe 31, leading into the heating coil disposed in the bottom o f the primary still B, heating the condensates flowing theieover from the inlet pipe 17, causing them to -give off their vapors dephlegmator B1 in passing through which they give off condensates that flow back through the pipes 32 through the check valve 16 into the primary still B, following a course therethrough previously described.

The vapors from the dephlegmator B1 pass upward through the outlet pipe 33 into the heating coil disposed in the bottom of the primary still E; the condensates from this coii passing into the separator 34 and flowing back through the pipe and the trap 36 into the dephlegmator B1, from which they fiow outward through the pipe 32 and mingle with the condensates from the dephlegmator passing back into the primary still B through the pipe 17. The

between the plates therein, flowing over the heating'coils disposed in the bottom of this still C; the heat of the coil driving olf the lighter fvapors until the condensates flovv down through the outlet pipe 45 into the pump 46. From the pump 46 the conden- 'sates are pumped-under pressure through the pipe 47 into the secondary still E, Where they flow through a tortuous course around the heating coils lin the bottom thereof, giving off their lighter vapors, the remaining condensates passing through the outlet into the pipe 48, flowing back through the check valve 16 and into the primary still B Wherein they give off their lighter vapors and iiow into the pipe 18, takingthe course previously described. The vapors. driven off in the secondary still E pass .through the pipe 38 to the condenser E', the product of Which is a f defined cut.

The original crude oil vapor entering the pipe 10 becomes gradually cooled as it passes from the primary still A giving 0H a cut at the separator 12, then passing on into the primary still B, giving ofi' a cut in the separator 39, then passing through the check valve 49, into the pipe 50 leading to the `heating' coil disposed in the bottom of the primary still C' wherein another condensate is formed and removed by the separator 51 from vWhich it -flows through the pipe 52 into the pump 53 and is forced under pressure therefrom throughthepipe 54 to the secondary still D making its tortuous 'Way over the heating coil in the bottom of thc secondary still D, giving off its vapors therein and flowing down through the outletV the pipe 56 into the primary still C, thevapors rising through the dephlegmator C1 pass into the pipe 57 and flow through the heating coil disposed in the. bottom of the secondary still D heating the condensates flowing therethrough and driving` o if the lighter vapors that pass through the pipe 58 connected with the condenser D', the products of which form a commercial out.

The condensates formed in the heating coil in the bottom of the secondary still D pass into the separator 60, from Which they flow back through the pipe 61, the trap 62, into the dephlegmator C. The lighter vapors passing the separator 60 into the pipe 63, pass to the condenser C. The vapors pass ing the last separator 51 pass into-the pipe 64' leading to a suitable condenser G, the product of which represents. a commercial cut in the process.

The apparatus shown and described con sisting of three sets of primary and second` ary stills', gives four distinct fractionations or cuts, one each from the stills D, E and F, and one from the primary heating coils discharging through the condenser G. The last cutthrough the condenser .G representing lighter cuts, such as gasolene, the specific gravity decreasing `With each of the secondary stills, D, E, F, in the order named, the by-produc'ts or residuum passing off through the pipe 23. The various sets of stills should be provided With safety valves as at 23', 24, 33', 38', 57 and 58, in each set to relieve any excess pressure that may be generated in the apparatus.

The by-passes leading into the primary heating coil pipe provide means for introducing crude vapors at reduced temperature at these points. For instance, if the crude oil vapor entering the -pipe 10 has a temperature, forvinstance, of 500o F, vapor' may be introduced at approximately 37 5 F. at the by-pass and at 250O F. at the bypass ai', or at temperatures about in these proportions.

In carrying out this process With the apparatus described, the original crude oil vapor is progressively cooled in its passage through the primary stills giving off' its conldensates at stated temperatures; which condensates are in'turn progressively heated in the secondary stills by the vapors given off `by their corresponding primary stills, whereby the heat given ofi in the primary still is utilized to refractionate the condensates therefrom, resulting in a high point of general efficiency in the apparatus, the only lost heat being that-necessary in the final condensers for condensing the variously defined fractional cuts. Vhereas the invention resides particularly Within the primary and secondarvdis-v tillingapparatus, it is to be understood that this apparatus operates in combination with crude oil stills for ,generating the crude oil vapor in the first instance, and With the condensers for the nal condensation of the fractional constituents.

Having thus described this invention, I claim.: l

1. The method of fractionating vapor consisting in progressively separating the vapor at certain tempeiatures during its passage to obtain condensates, fractionally distilling each successive condensate by the heat of the vapor previously separated therefrom, wlieieby an additional condensate and an additional vapor are obtained, and in further heating each successively formed condensate by the heat of lvapor of the next previously formed condensate.

. Q9. The method of fractionating vapor consisting in progressively separating condensates from the vapor at certaintemperatures during its passage, raising the teinperatui'e of the vapor separated from each condensate, fractionally distilling each successive condensate by the heat of vapor previously separated therefrom to obtain an additional condensate-and an additional vapor, and in further heating each of the successively formed condensates in reversed progressiveorder by the heat of vapor of' next previously formed condensate.

3. A refractional distilling apparatus coinprising a series of primary stills having means for progressively coolingvapor in its passage therethrough' to obtain condensates, and a series of secondary stills having means for heating said condensates by the heat given off by the vapor in. corresponding' primary stills.

4. A refractional distilling apparatus comprising a series of primary stills having means for progressively cooling vapor iii its passage therethrough to obtain condensates, a series of secondary stills having means for heating said condensates by the heat given oif by the vapor in corresponding primary stills, and means between each corresponding primary and secondary still whereby the condensate from the secondary still may be refractioned by the heat given off in the primary still. i i,

A refractioiial distilling apparat-iis comi prising a series of primary stills "having means for progressively cooling vapor iii 'its passage therethrough to obtain condensates, a series of secondary stills having means for heating said condensates by the heat given off by vapor in corresponding primary stills, and means between each corresponding primary and secondary still whereby the'condensates from both the primar i andthe secondary stills are refractiona-ted by the heat given olf in the primary still.

6. A fractional distillation apparatus iiicluding a series of primary stills and a series of secondary stills; heating means in said stills; separators connected with said heating means and discharging into the succeeding primary stills; certain of said primary stills discharging into said secondary stills and condensers connected with said secondary stills.

7. A fractional distillation apparatus including a series of primary stills; intercommunicating heating means in said primary stills; separators in said heating means between said primary stills and discharging' into the succeeding primary still; a series of secondary stills; heating means in said sec- 4 ondary stills communicating with saidv r1.,- 'f

mary stills; and condensers connecte' each secondary still. Y y, i S. A fractional distillation apparatus iiicluding a series of primary stills; intercom-v municating heating means in said stills; separators in said heating means between said stills and discharging into the succeeding still; a series of secondary stills having heating meansv therein connected with the adjacent primary still; and separators in said heatingA means in the secondary stills and communicating with the adjacent primary still.

9.. A fractional distillation apparatus including a series of primary stills, so connected that the condensates of one still discharges into the succeeding primary still; secondary stills connectedto each primary still so that the vapors from the primary still flow through heating means in the secondary still the condensates therefrom flowing back into the primary still; andy piflim'ary still, means for returning the condensates from the secondary stills 'back into theadjacent primary still; and means for 5 condensing the fractional vapors of each secondary still.

1l. A .fractional distillation apparatus including a series of primary stills having heating means therein; separators in said heating means between said stills; means for flowing the condensates from said separators over the heating means in the succeeding primary still; secondary stills having heating means therein; dephlegmators interposed between the primary stills andv their" `adjacent secondary still; separators connected with the heatingmeans in the secondary stills and discharging back into their adjacent primary stills; means for flowing the condensates from each primary still over the heating means in the secondary still of the preceding primaryxstill; and means for condensing the fractional vapors from each secondary still.

to f

1Q. A fractional distillation apparatus including primary stills and secondary stills arranged in sets; heating means in said primary and said secondary stills; means for flowing the condensates from the heating means in the primary stills over the heating means in the succeeding primary still; means for flowing the vapors from the'primary stills through the heating means in the secondary still of that set; means for flowing the condensates from each primary still over the heating means in the secondary still of the precedlng set; and means for condensing the fract1onal vapors of each secondary still.

13. A fractional distillation apparatus including primaryv stills and secondary stills arranged in sets; heating means in said primary and said secondary stills; means for flowing the condensates from the heating means in the primary Stills over the heating means in the succeeding primary still; means for flowing 'the vapors from the primary stills through the heating means in the secondary still of that' set'; means for flowing the condensates from each primary still over the heating means in the secondary still of the preceding set; means for flowing the condensates from each secondary still back into the primary still of its set; and means for condensing the fractional vapors of each secondary still.

14. A fractional distillation apparatus including primary stills and .secondary stills arranged in sets; heating means in said primary and said secondary stills; means for flowing the condensates from the heating means in the primary stills over the heating means in the succeeding primary still; means for flowing the vapors from the primary stills through the heating means in the secondary still of that set; means for flowing the condensates from each primary still over theV heating means in the secondary still of the preceding set; means for flowing the condensates from each secondary still back into the primary still of its set; means for flowing the condensates from the heating means of the secondary stills back into the primary still of that set; and means for condensing the fractional vapors of each secondary still.

15. A fractional distillation apparatus including primary stills and secondary stills arranged in sets, heating means in said primary and said secondary stills; means for flowing the condensates from the heating means in the primary stills overthe heating means in the succeeding primary still; means for flowing the vapors from the primary stills through the heating means in the secondary still of that set; means for flowing the condensates from each primary still over the heating means in the secondary still of the preceding set; means for flowing the condensates from each secondary still back into .the primary still of its set, in combination with a crude vapor still connected `with the -heating means in the rst primary still.

' 16. A fractional distillation apparatus including primary stills and secondary stills arranged in'sets, heating means in said prima and said secondary stills; means for flowmg the condensates from the heating means in the primary stills over the heating means in the succeeding primary still; means for flowing the vapors from the primary still's through the heating means in the lsecondary still of that set; means for flowing the condensates from Veach primary still over the heating means in the secondary still of the preceding set; means for* flowing the condensates from each secondary still back into the primary still of its set; in combination with crude vapor stills connected with the heating means insaid pri mary stills at intervals between said primary stills.

In testimony whereof, I have hereunto set my hand at San Francisco, California,

this 2nd day of March, 1916.

. VINCENT T. GILCHRIST. In the presence of- BALDWIN VALE,- VIcToR ETIENNE, J r. 

